Impact of Chemistry - Rutgers NB

Matter

Tangible material that makes up everything in the universe

Atom

The smallest unit of matter that cannot be broken down (except in nuclear reactions)

Scientific Method

The general approach used for scientific experimentation worldwide

Steps of Scientific Method

1. Observation
2. Hypothesis
3. Experiments
4. Data Collection
5. Theory

Hypothesis

An initial best guess about your observation that can be tested by experiment

Theory

Detailed explanation of the experimental results. Cannot be proved

Dimensional Analysis

A method that uses conversion factors to convert from one unit to another

Atoms

3 Types of Particles : positive, negative and neutral
The number of pos. particles equal number of neg. particles

Atom Structure

- Dense positively charged nucleus (location of pos. protons and neutral neutrons)
- Cloud-like smear of negative charge around nucleus (location negatively charged electrons)

Atomic Number

Is equal to the number of protons an atom has

Periods

Horizontal rows in periodic table

Groups/Families

Vertical columns in periodic table

Protons + Neutrons =

Mass number (superscript number)

Isotopes

Atoms that have the same number of electrons, the same number of protons, but different numbers of neutrons

Mass Number - Number of Protons =

Neutrons

Uses for Isotopic Percentages

Carbon Dating, Forensic Analysis, Identification of the Origin of a Sample of Matter

Number of Electrons =

Number of Protons

Ground State

Lowest energy level of a particular electron

Excited State

When an electron is energized, moves to a higher energy level

Radiant Energy

Energy given off in the form of light when electrons relax and return to a lower energy level (Depends on the difference between energy levels)

Electromagnetic Spectrum

Different types of light on the scale

Wavelength

How light is classified; distance from one peak to the next of a wave; the shorter the more energetic

Line Spectrum

Pattern of lines of light that is characteristic of a given element; Specific wavelengths, given of by a specific element, of light that correspond to the spacing between energy levels of atoms

Periodic Table Parts

Metals, Nonmetals, Metalloids

Metals

Mostly shiny solids; malleable, ductile, conduct electricity

Nonmetals

Mostly solids and gases; brittle, not malleable or ductile, do not conduct electricity

Metalloids

Found in semiconductors - these materials conduct electricity in certain conditions

Organic Substances

Carbon based

Inorganic

Not carbon based

Pure Substance

A specimen of matter that contains only a single element or compound

Mixture

Defined as one or more pure substances combined together

Heterogeneous Mixtures

Mixtures with boundaries we can see

Homogeneous Mixtures

Mixtures that are uniform in appearance

Pure Substance - Element

Contains atoms from only one element

Pure Substance - Compound

Contains atoms from more than one element

Law of Constant Composition

A given compound has a fixed and definite number of atoms of its constituent elements

Lone Pair

A pair of electrons in a Lewis Dot Structure, also called nonbonding pair

Ionic Bond

Formed when one or more electrons are transferred from one atom to another

Covalent Bonding

sharing of electrons

Ion

Electrically charged atom

Cation

Positively charged ions

Anion

Negatively Charged ions

Covalent Bonds

Occur when electrons are shared between two atoms

Diatomic Molecule

A covalent bond between atoms of the same element

Nonpolar Covalent Bond

Bond between atoms of the same element; no lopsidedness in electron sharing

Polar Covalent Bonds

An unequal sharing of electrons in the bond

Bond Polarity (Most polar to least)

1. Ionic Bonds
2. Polar Covalent Bonds
3. Nonpolar Covalent Bonds

Metallic Bonds

Bonds within a pure chunk of metal; form a sea of negative charge - electrons move through the whole lattice of cations

Determining Electronegativity

Large: ionic bond
Moderate: polar covalent bond
Negligible: nonpolar covalent bond

Allotropes

two or more different molecular forms of the same element in the same physical state

crystalline solid

A solid that is made up of crystals in which particles are arranged in a regular, repeating pattern

amorphous solid

A solid made up of particles that are not arranged in a regular pattern

Transparent solid

solids that allow the transmission of light through them.
The particles are arranged in a way that does not scatter or absorb light significantly

What country is the leading producer of rare earth metals

China

Cradle-to-Grave Recycling

collecting and reusing materials at the end of their life cycle, preventing them from going to waste or a landfill. The materials are typically downcycled into lower-value products or disposed of.

cradle to cradle recycling

materials are continually recycled into new products of equal or higher value without producing waste.

Layers of the atmosphere

exosphere, thermosphere, mesosphere, stratosphere, troposphere

Exosphere

The outer layer of the thermosphere, extending outward into space.

Thermosphere

The outermost layer of Earth's atmosphere.

Mesoshpere

the strong, lower part of the mantle between the asthosphere and the outer core.

Stratosphere

The second-lowest layer of Earth's atmosphere.

Troposphere

The lowest layer of Earth's atmosphere

Gases that make up air

nitrogen (biggest part- 78%), oxygen (21%), others: water vapor, argon, carbon dioxide, other things

air inversion

When cooler air is trapped under warmer air. Pollutants can accumulate here

Air Quality Index

a scale that ranks levels of ozone and other air pollutants

chemical reaction

the rearrangement of atoms when reactants are transformed into products.

How does acid rain form?

air pollutants combine with water vapor to create acids, which mix with rainwater and fall to the ground, causing environmental harm.

Catalytic converters

Used in a car to convert toxins such as CO, NO, NO2 and hydrocarbons to harmless gases, like nitrogen and carbon dioxide.

common sources of indoor air pollution

- tobacco smoke
- Rados gass
- mold and mildew

green chemistry

the design of products and processes that reduce hazardous substances.

Sustainability

The ability to keep in existence or maintain. A sustainable ecosystem is one that can be maintained

explain the relationship between the speed of light, wavelength and frequency

the speed of light is equal to the product of the wavelength and frequency.

If the wavelength (λ) increases, the frequency (f) decreases, and vice versa.

The product of wavelength and frequency is always equal to the speed of light, which remains constant.

relationship between the energy of electromagnetic radiation andits frequency or wavelength

-The energy of electromagnetic radiation, like light, is directly related to its frequency.
-The higher the frequency, the higher the energy.
-Wavelength is the opposite: shorter wavelengths have higher frequencies and more energy, while longer wavelengths have lower frequencies and less energy.

UVB radiation

290 to 320 nanometers. It has shorter, burning wavelengths that are stronger and more damaging than UVA rays. It causes burning of the skin as well as tanning, skin aging, and cancer.

most is absorbed in the ozone

UVA radiation

320 to 400 nanometers that penetrate deeper into the skin
Reaches Earth's surface in thegreatest quantity and penetratesfarthest into the skin

UVC radiation

200 to 280 nm
most dangerous type of UV radiation

ozone hole

A thinning of stratospheric ozone that occurs over the poles during the spring